The invention relates to a heated trough mangle, especially a multiple trough mangle for the drying and smoothing of damp pieces of laundry.
Heated trough mangles are already known, in which the steam-air-mixture, formed in the operating zones between the mangle cylinders and the mangle troughs, is suctioned off as exhaust air. For this purpose, the mangle cylinder usually has a perforated mantle surface and a hollow pivot bearing, connected to an outlet arrangement (DE-PS No. 131 918).
This exhaust air contains a considerable amount of unused heat; heat, which otherwise has to be produced continuously by the heating system of the heated trough mangle.
A heated trough mangle is already known, in which at least part of this exhaust air is subsequently used (DE-PS No. 468 074). In this mangle, the outlet pipe connected to the mangle cylinder leads to a duct of a heat exchanger via a fan, with the heat exchanger adapted to transfer heat from one air stream to another. For this, the heat exchanger has a second duct, through which, by means of an additional fan, fresh air is forced, which has been suctioned from the area surrounding the steam trough mangle. The fresh air heated in this manner is then carried to two boxes, arranged in front of and behind the mangle trough and having sievelike perforated places for the exit of the fresh air. The fresh air releases its heat in the zone of these boxes to the laundry passing through, thus pre- or post-drying it.
It is disadvantageous when the heat exchanger is arranged separate from the mangle and at a considerable distance from it. This leads to either large heat losses when conveying the exhaust air from the mangle cylinder to the heat exchanger or considerable cost when isolating the corresponding pipes for heat. The requirement for large space and construction costs are added to this. The warm air flowing into the mangle surroundings, following contact with the laundry to be dried, constitutes an unacceptable stress on the servicing personnel of the heated trough mangle. Furthermore, the considerable amount of heat still contained in the fresh air is thus finally, irrecoverably lost.
DE-OS No. 28 14 618 describes an ironing apparatus, in which the fresh air, having been heated in a heat exchanger by the exhaust air from the mangle cylinders and the condensate produced when heating the mangle troughs, is conveyed to the mangle chamber in the vicinity of a spiral-trough-unit (mangle unit). However, this ironing apparatus has the disadvantage of an external positioning of the heat exchanger with all the already mentioned consequences.
It is common practice to increase the capacity of heated trough mangles by adding additional mangle units, resulting in relatively low cost. This is not possible in the ironing apparatus, according to DE-OS No. 28 14 618.
It is the object of the invention to reduce the energy losses in heated trough mangles, while at the same time avoiding environmental stress.
It is the object of the invention to produce a heated trough mangle, which allows intensive use of the heat contained in the exhaust air, in which the heat recovery system is located inside the heated trough mangle in order to save space, and to which additional mangle units can be added at any time in the future.